A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly and others), is a rechargeable battery of lithium-ion technology using a polymer electrolyte instead of a liquid electrolyte. These batteries provide higher specific energy than other lithium battery types and are used in applications where These batteries provide higher specific energy than other lithium battery types and are used in applications where weight is a critical feature, such as mobile devices, radio-controlled aircraft and some electric vehicles.

How they work

Like other lithium-ion batteries, LiPos work by embedding and disengaging lithium ions from the cathode and anode materials, with a liquid electrolyte providing the conductive medium. To prevent the electrodes from coming into direct contact with each other, a microporous spacer is located between them, allowing only the ions, but not the electrode particles, to migrate from one side to the other.

Applications

LiPo cells offer compelling advantages to manufacturers. They can easily produce batteries in almost any desired shape. For example, the space and weight requirements of mobile devices and laptops can be met. They also have a low self-discharge rate of about 5% per month.

Drones, radio control equipment and aircraft

Lithium polymer batteries are now almost ubiquitous for powering commercial and hobby drones (unmanned_aerial_vehicles ), radio-controlled aircraft, radio-controlled cars, and large model trains, where their lighter weight and increased capacity and power output justify the price. Test reports warn of fire risks if batteries are not used according to instructions.

Long-term storage voltages for lithium polymer batteries used in R/C models should be in the range of 3.6 to 3.9V per cell, otherwise the battery may be damaged.

Lithium polymer battery packs are also widely used in airguns, and their higher discharge current and better energy density provide a very significant performance boost (higher firing rate) compared to more traditional NiMH batteries. High discharge currents do damage the switch contacts due to arcing (resulting in oxidation of the contacts and frequent carbon deposits), so it is recommended that solid-state MOSFET switches be used or that the trigger contacts be cleaned regularly.

Personal Electronics

Lithium polymer batteries are prevalent in mobile devices, mobile power supplies, ultra-thin laptops, portable media players, wireless controllers for video game consoles, wireless PC peripherals, electronic cigarettes and other applications that require small size and high energy density over cost considerations.

Electric Vehicles

Hyundai Motor Company uses this type of battery in some of its electric and hybrid vehicles, as well as Kia Motors uses this type of battery in its electric Kia Soul. The Bolloré Bluecar, used in car-sharing programs in several cities, also uses this type of battery.

Uninterruptible power supply systems

Lithium-ion batteries are becoming more common in uninterruptible power supply (UPS) systems. They offer many advantages over traditional VRLA batteries, and confidence in the technology is growing as stability and safety improve. Their power to size and weight ratio is seen as a major advantage for many industries requiring critical power backup, including data centers where space is often at a premium. Longer cycle life, available energy (depth of discharge) and thermal runaway are also seen as advantages of using lithium polymer batteries over VRLA batteries.

Starters

Batteries used to start vehicle engines are typically 12V or 24V, so portable jumper starters or battery boosters use three or six lithium polymer batteries (3S1P/6S1P) connected in series to start the vehicle in an emergency rather than other jumper starting methods. Lead-acid starters are less expensive, but they are larger and heavier than their lithium counterparts, so most of these products have switched to lithium batteries, and sometimes lithium iron phosphate.